The present invention relates to gas control valves used in cooking utensils similar to gas stoves and the like, that use a central plug to control the volume of gas through the control valve.
There are a number of variations in the construction of gas valves. These valves have maximum gas flow settings, (assigned to the completely open setting of a burner) and minimum gas flow settings (assigned to the lowest level of load of the same burner), as well as an intermediate setting. Normally these gas valves have an inlet orifice that allows the in-coming gas to flow towards an outer mantle of the operating element (valve plug/gas valve plug).
The operating element, or valve plug, has a number of holes bored into it so that all the gas will discharge into a gas outlet area. When the plug is turned 90xc2x0 in the valve housing, the holes in the plug overlap with the gas inlet hole in the valve gas valve body, and this allows the maximum quantity of gas to flow through the gas valve. When the valve is set for the minimum flow position of a burner; an additional hole with a specified dimension is bored into the plug so that further turning of the plug in the valve housing will orient the additional hole located in the plug, into alignment with the hole in the valve housing, at the gas inlet hole of the valve housing.
In order to provide for an intermediate gas flow setting, i.e. a gas flow between the maximum flow setting and the minimum flow settings, the plug is turned so that holes of various dimensions, which have been drilled through the plug, are positioned at the gas inlet hole of the valve housing, thereby switching the gas valve to a high, medium high, medium, medium low , or low setting. These various settings are achieved by turning a valve knob that is installed on the plug.
In order to prevent the gas flame from being extinguished during the switching process, the holes that are drilled in the plug are positioned close enough together to allow at least two of the holes drilled in the plug to overlap with the gas inlet in the valve housing. A primary disadvantage of having two holes overlap with the gas inlet is that there is a short stretch of the switching path where gas from both holes will flow through the plug at the same time.
In the current state of the art of gas valve design, there are gas valves that are capable of achieving linear regulation. These gas valves do so by having a diagonal channel machined on the outer circumference of the plug. A bypass hole is placed near a fixed gas jet in order to guarantee a low pressure setting of the valve. The gas jet has a predetermined and fixed dimension for the low setting. An additional channel directs gas back to the plug. A further additional channel directs the gas to the gas outlet of the valve. The linear regulation of the gas flow is achieved by using the diagonally located channel, which is located in the plug, and begins at the hole in the plug for the high setting. The gas flow is gradually reduced during the switching process (turning). The plug is positioned in front of the gas inlet hole in the valve housing.
This type of construction is quite expensive to produce, because of the extra jet necessary to guarantee the low position. This type of construction is also inexact, because of the valve housing""s diametrical relationship to the constriction diameter required on a short switching path.
U.S. Pat. No. 5,551,467 by Booth et al., dated Sep. 3, 1996, discloses a Ball Valve with Controlled Flow Variation. This invention uses a ball that is attached to an actuator handle that can be manually or mechanically actuated. The ball has a passageway that has been specifically sized for the flow fluid. The ball has a discharge orifice having a multi-shaped cutout. This multi-shaped cutout provides for controlled variation of the fluid flow. This patent differs from the present disclosure in that the control valve has a simple circular inlet in the ball valve, while the exit is the compound shape that offers varying flow characteristics based upon the angular position of the exit in relationship to the inlet. The ball valve uses a direct inlet to exit orientation where the fluid flow makes no apparent turns but flows straight through the valve. The present disclosure contains a plug that has an inlet at the bottom of the plug and exits perpendicular to a longitudinal axis of the plug.
U.S. Pat. No. 4,699,358 by Iqbal, dated Oct. 13, 1987, discloses a Faucet Valve with Noise Reduction Structure. This patent is specific for reducing or suppressing noise when water is flowing through the valve. The sleeve member in the 358 patent has an outlet on the side of the sleeve member, which is generally oval in shape, that allows the fluid to exit. The seal support, which is mounted in the sleeve member and is capable of rotating about its axis, allows water to enter from the bottom of the seal support. The stem has an inner piston, which has an inlet port and an exit port, that allows the water to exit through the outlet in the sleeve member.
U.S. Pat. No. 4,102,357 by Charlton, dated Jul. 25, 1978, discloses Variable Flow Outlet Valves. This patent discloses a valve body assembly consisting of 2 cylindrical bodies separated by a space, wherein the space is filled with a compressed porous material. An interior tubular outlet sleeve communicates with various vents that provide specific mass flow for the air. This patent is specific for low noise air vents in aircraft cockpits and would not be adaptable to provide smooth linear flow to provide gas for appliances. The outlet valve is designed to reduce the noise inherent with air flow systems in aircraft.
U.S. Pat. No. 4,947,891 by Genbauffe, dated Aug. 14, 1990 discloses a Fuel Control Device, a Fuel Control System Using the Device and a Method of Making the Device.
The following description is provided to enable a person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor for carrying out his invention. Various modifications, however, will be readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide for an improved gas valve.
The object of this invention was to create a regulating gas valve that has an improved ability to provide fuel to gaseous operated burners in a such a manner as to provide a smooth and even gaseous fuel flow as possible between the high setting and low setting.
A further object of this invention to create a regulating gas valve that does not require an additional jet to be present in order to operate at the low setting.
The objects of this invention are achieved by having a main gas inlet of the valve body provide a hole in a valve plug with gas venting through the hole when the valve is positioned at the maximum flow setting. Adjacent to this hole in the valve plug is a linear canal. The linear canal is machined into the valve plug and positioned at a right angle to the center axis of the valve plug. The linear canal terminates along the circumference of the valve plug, where the gas valve is designed to provide its lowest setting. A hole, with a pre-determined and fixed diameter, is bored into the valve plug for the minimum flow setting at this location. Both the maximum flow settings and the minimum flow settings of the gas regulation valve are defined by this process, i.e. drilling a hole with a pre-determined fixed diameter into the plug. There is a fixed diameter hole for the maximum flow setting and a fixed diameter hole for the minimum flow setting.
A diagonally located channel is machined in the plug and is positioned around the axis of the plug. The diagonally located channel then discharges the gaseous fuel directly at the gas outlet. This diagonally located channel runs around the plug and is supplied with gas from the gas inlet of the valve body from the predetermined fixed diameter hole.
The further the plug is turned in the body from high setting to low setting, the more the channel located in front of the fixed predetermined diameter hole is masked. The chosen angle to machine the diagonally located regulating channel assures that, prior to achieving the low setting in the switching path, the channel is constricted completely and is therefore no longer supplied with gas.
The advantage of constructing the valve body (valve plug) in this matter is that the linearity of the regulation curve between the maximum flow setting and the minimum flow setting provides a finer adjustment of the gas flow, because of the method of restricting the gas supply hole in the regulation channel in the plug.